1. Field of the Invention
The present invention relates to vehicles suitable for traveling over rough terrain.
2. Description of the Related Art
Vehicles suitable for traveling over rough terrain are conventionally known. Included among such vehicles are an all-terrain vehicle (ATV) and a recreational off-highway vehicle (ROV). For example, U.S. Pat. No. 7,461,851 B2 discloses an ROV including rear wheels, a rear frame, upper arms, lower arms, and shock absorbers. The rear wheels are supported by the rear frame via the upper and lower arms. The shock absorbers are connected to the rear frame and the lower arms.
Each shock absorber is arranged so that its upper end portion is disposed outward of the rear frame. Such an arrangement reduces the widthwise distance between each rear wheel and the upper end portion of the associated shock absorber. To enable each shock absorber to have a sufficient stroke, a sufficient widthwise distance must be provided between each rear wheel and a frame portion to which the upper end portion of the associated shock absorber is attached. For example, one possible approach to increasing the widthwise distance between each rear wheel and the upper end portion of the associated shock absorber is to dispose each rear wheel farther outward in the width direction of the vehicle. Unfortunately, such an approach increases the widthwise length of the vehicle. U.S. Pat. No. 6,695,329 B2 discloses an ROV including rear frames, shock absorbers, seat pipes, pivot shafts, upper arms, auxiliary pipes, and a final reduction gear. The upper end portions of the shock absorbers of this ROV are disposed inward of the rear frames. The upper end portions of the shock absorbers are connected to the seat pipes.
In a rear view of the vehicle, the pivot shafts, which support the upper arms, are disposed inward relative to the rear frames in the width direction of the vehicle. The auxiliary pipes, to which the pivot shafts are attached, are each disposed at a high position so as to prevent interference between the auxiliary pipes and the upper arms and between the auxiliary pipes and the final reduction gear. This disadvantageously reduces the space between the auxiliary pipes and the seat pipes. This space is used when the shock absorbers oscillate. If this space is small, the shock absorbers have a narrow operating range and thus cannot deliver satisfactory performance.